No power on SSB
开云体育I have had this I will get back to you, I presume AM is dead too? ? From: [email protected] [mailto:[email protected]] On Behalf Of Suryono Adisoemarta via groups.io
Sent: 03 August 2022 02:28 To: [email protected] Subject: [YaesuFT847] No power on SSB ? I need help as I have no power on SSB (all bands), whereas FM is fine, whenever I transmit on my FT-847. Receiving SSB signal is fine. ? I've confirmed this problem on a watt meter to a dummy load. ? Is there a relay to change modulation mode that might be stuck ? ? 73 de Yono - YD0NXX ? |
开云体育Audio tracing will not work as the pre amp uses current mirrors, so very little to see, as AM works, the 2nd TX mixer is locked, so check around the SSB filters with a scope for the SSB signal. ? It would not hurt to do the following ? ? 73 ? Andrew ? From: [email protected] [mailto:[email protected]] On Behalf Of Suryono Adisoemarta via groups.io
Sent: 03 August 2022 09:44 To: [email protected] Subject: Re: [YaesuFT847] No power on SSB ? Andrew, thanks for the response. ? AM (and FM) works fine, only on SSB I got nothing. I just pried open the box and starting doing the audio tracing. ? 73 de Yono - YD0NXX ? On Wednesday, August 3, 2022 at 03:00:20 PM GMT+7, Andrew Lenton <a@...> wrote: ? ? I have had this I will get back to you, I presume AM is dead too? ? From: [email protected] [mailto:[email protected]] On Behalf Of Suryono Adisoemarta via groups.io ? I need help as I have no power on SSB (all bands), whereas FM is fine, whenever I transmit on my FT-847. Receiving SSB signal is fine. ? I've confirmed this problem on a watt meter to a dummy load. ? Is there a relay to change modulation mode that might be stuck ? ? 73 de Yono - YD0NXX ? |
开云体育Might find this useful ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Suryono Adisoemarta via groups.io
Sent: 03 August 2022 09:44 To: [email protected] Subject: Re: [YaesuFT847] No power on SSB ? Andrew, thanks for the response. ? AM (and FM) works fine, only on SSB I got nothing. I just pried open the box and starting doing the audio tracing. ? 73 de Yono - YD0NXX ? On Wednesday, August 3, 2022 at 03:00:20 PM GMT+7, Andrew Lenton <a@...> wrote: ? ? I have had this I will get back to you, I presume AM is dead too? ? From: [email protected] [mailto:[email protected]] On Behalf Of Suryono Adisoemarta via groups.io ? I need help as I have no power on SSB (all bands), whereas FM is fine, whenever I transmit on my FT-847. Receiving SSB signal is fine. ? I've confirmed this problem on a watt meter to a dummy load. ? Is there a relay to change modulation mode that might be stuck ? ? 73 de Yono - YD0NXX ? |
开云体育This is the 2nd TX mixer VCO PLL used for SSB and AM, this mixes with the 1st IF SSB to form the 2nd TX IF frequency, before it is mixed up to final frequency by the UHF TX VCO. ? T1008 has been known to drift, sometime tweaked by mistake ! then it goes out of lock ? ? Check TP 1003 is correct. ? ? ? ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Suryono Adisoemarta via groups.io
Sent: 03 August 2022 09:44 To: [email protected] Subject: Re: [YaesuFT847] No power on SSB ? Andrew, thanks for the response. ? AM (and FM) works fine, only on SSB I got nothing. I just pried open the box and starting doing the audio tracing. ? 73 de Yono - YD0NXX ? On Wednesday, August 3, 2022 at 03:00:20 PM GMT+7, Andrew Lenton <a@...> wrote: ? ? I have had this I will get back to you, I presume AM is dead too? ? From: [email protected] [mailto:[email protected]] On Behalf Of Suryono Adisoemarta via groups.io ? I need help as I have no power on SSB (all bands), whereas FM is fine, whenever I transmit on my FT-847. Receiving SSB signal is fine. ? I've confirmed this problem on a watt meter to a dummy load. ? Is there a relay to change modulation mode that might be stuck ? ? 73 de Yono - YD0NXX ? |
开云体育Aloes check around the balanced modulator, of the SSB signal PINs 2&5 are interchangeable as it’s is a gilbert cell, Yaesu used it the other way around! ? Check the filter pins are not corroded ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Suryono Adisoemarta via groups.io
Sent: 03 August 2022 09:44 To: [email protected] Subject: Re: [YaesuFT847] No power on SSB ? Andrew, thanks for the response. ? AM (and FM) works fine, only on SSB I got nothing. I just pried open the box and starting doing the audio tracing. ? 73 de Yono - YD0NXX ? On Wednesday, August 3, 2022 at 03:00:20 PM GMT+7, Andrew Lenton <a@...> wrote: ? ? I have had this I will get back to you, I presume AM is dead too? ? From: [email protected] [mailto:[email protected]] On Behalf Of Suryono Adisoemarta via groups.io ? I need help as I have no power on SSB (all bands), whereas FM is fine, whenever I transmit on my FT-847. Receiving SSB signal is fine. ? I've confirmed this problem on a watt meter to a dummy load. ? Is there a relay to change modulation mode that might be stuck ? ? 73 de Yono - YD0NXX ? |
开云体育Well done for finding this, I wonder what killed the amps, check the 8V and 5V rails! ? 73 ? Andrew ? From: [email protected] [mailto:[email protected]] On Behalf Of Suryono Adisoemarta via groups.io ? A quick update as a closure to the no SSB problem. After I got help by a friend in tracing the audio signal, we had to replace the NJM2902 op-amps. I went ahead and replace both chips. |
Andrew Lenton